title: Two classes of ovarian primordial follicles exhibit distinct developmental dynamics and physiological functions.
abstract: In the mammalian ovary, progressive activation of primordial follicles serves as the source of fertilizable ova, and disorders in the development of primordial follicles lead to various ovarian diseases. However, very little is known about the developmental dynamics of primordial follicles under physiological conditions, and the fates of distinct populations of primordial follicles also remain unclear. In this study, by generating the Foxl2-CreER(T2) and Sohlh1-CreER(T2) inducible mouse models, we have specifically labeled and traced the in vivo development of two classes of primordial follicles, the first wave of simultaneously activated follicles after birth and the primordial follicles that are gradually activated in adulthood. Our results show that the first wave of follicles exists in the ovaries for ∼3 months and contributes to the onset of puberty and to early fertility. The primordial follicles at the ovarian cortex gradually replace the first wave of follicles and dominate the ovary after 3 months of age, providing fertility until the end of reproductive life. Moreover, by tracing the time periods needed for primordial follicles to reach various advanced stages in vivo, we were able to determine the exact developmental dynamics of the two classes of primordial follicles. We have now revealed the lifelong developmental dynamics of ovarian primordial follicles under physiological conditions and have clearly shown that two classes of primordial follicles follow distinct, age-dependent developmental paths and play different roles in the mammalian reproductive lifespan.
authors.affiliation: Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg SE-405 30, Sweden.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Zheng
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.forename: Nagaraju
authors.initials: N
authors.lastname: Gorre
authors.forename: Sanjiv
authors.initials: S
authors.lastname: Risal
authors.forename: Yan
authors.initials: Y
authors.lastname: Shen
authors.forename: Kui
authors.initials: K
authors.lastname: Liu
mesh_terms: D000375:Aging; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000096:biosynthesis / Q000235:genetics; D058948:Cell Tracking; D005260:Female; D005298:Fertility; D000074842:Forkhead Box Protein L2; D051858:Forkhead Transcription Factors / Q000096:biosynthesis / Q000235:genetics; D055879:Gene Knock-In Techniques; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009865:Oocytes / Q000378:metabolism; D006080:Ovarian Follicle / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D012741:Sexual Maturation
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D000074842:Forkhead Box Protein L2; D051858:Forkhead Transcription Factors; C498893:Foxl2 protein, mouse; C511466:Sohlh1 protein, mouse